JP2537636B2 - Magnetic assembly and method of manufacturing the same - Google Patents

Abstract

A rotor (85) assembly for a permanent magnet motor includes a set of laminations forming a rotor body, each lamination having a first magnet slot (97) therein. A generally rectangular permanent magnet is disposed in the magnet slot (97), the magnet slot (97) of each lamination being shaped so as to receive the rectangular permanent magnet through all the skewed laminations with a minimum air gap. A method of making an assembly such as a rotor (85) includes the steps of providing an assembly body made of ferromagnetic material defining at least one magnet slot (97) therein. The slot is at least partially filled with a mixture of magnetizable particles in a binder. The mixture is compressed and then cured to bond the magnetizable particles together in the slot (97) and the bonded part icles are then magnetized in the slot (97) to form a magnet in situ in the slot (97) without an air gap.

Description

The present invention relates to a magnetic assembly including a combination of a magnet and a magnetic plate laminated body used in various devices such as an electric motor and a speaker.

PRIOR ART By way of example, a rotor assembly for a synchronous rotary electric motor includes a stack of individual magnetic plates constructed of suitable ferromagnetic materials. Each magnetic plate has a central hole through which the rotary shaft passes, a plurality of peripheral holes adjacent to the outer edge, and a magnet slot formed in the middle thereof. A stack of magnetic plates is placed in a die-cast mold, molten aluminum is poured to surround it, and a solidified body of molten aluminum fills the passage formed by the peripheral holes to form the rotor conductor rod. The assembled magnetic plates are assembled into a laminated body. A preformed permanent magnet, generally in the shape of a rectangular rod, is mounted in the magnet slot.

[Problems to be Solved by the Invention] These rod-shaped permanent magnets must be mounted in a magnet slot and appropriately fixed therein. In this case, in order not to prevent the insertion of the magnets into the magnet slots of all the magnetic plates regardless of the manufacturing error of each magnet and the drilling error of each magnet slot,
The difference between the standard dimensions of the magnet slot and the standard dimensions of the magnet,
That is, the size of the gap left between the two must be considerably large. However, leaving such a large gap between the magnet slot and the magnet is not preferable from the standpoint of increasing the magnetic flux density of the laminated body and firmly attaching the magnet to the laminated body.

In view of the above problems, the present invention provides a magnetic plate laminate by incorporating magnets without leaving any gaps in the magnet slots of the magnetic plate laminate formed by the magnet slots of each magnetic plate, that is, in the magnet incorporating space. It is an object of the present invention to provide a magnetic assembly comprising a combination of a magnet and a magnetic plate laminated body, which can increase the magnetic flux density and can securely fix the magnet to the magnetic plate laminated body, and a manufacturing method thereof.

[Means for Solving the Problem] According to the present invention, the above-mentioned problem is that a magnetic plate having magnet slots formed therein is provided with corresponding magnet slots in which the respective magnet slots are substantially aligned with each other. A magnetic assembly having a stack of magnetic plates stacked in such a manner, and a permanent magnet piece in which powder of a ferromagnetic material filled in a magnet slot of the stack is hardened and magnetized in the slot, And a step of stacking magnetic plates each having a magnet slot so that the magnet slots are substantially aligned with each other to form a laminate having a corresponding magnet slot formed therein; Filling the ferromagnetic material powder, compressing and hardening the ferromagnetic material powder in the magnet slots of the laminate to form a solid body of the ferromagnetic material, and magnet And magnetizing the solid body of ferromagnetic material in the slot.

[Operation and Effect of the Invention] By configuring the magnetic assembly as described above, the space inside the magnet slots formed in the laminated body of magnetic plates is defined by the size or size of the magnet slots formed in each magnetic plate. Even if there is some difference in the above, the entire space is completely filled with the powder of the ferromagnetic material, and the powder filler is hardened and magnetized to form the laminate in the laminate. An assembly of a magnet and a laminate of magnetic plates is obtained, which incorporates permanent magnet pieces that come into close contact with any of the magnetic plates and achieve a high magnetic flux transfer coefficient therebetween.

Further, since such a magnetic assembly is manufactured in the above-mentioned manner, the laminated body formed by stacking the magnetic plates also functions as a molding die for molding the powder of the ferromagnetic material into the magnet piece,
Furthermore, since it also functions as a magnetic conductor for magnetizing the ferromagnetic material piece formed in the magnet slot of the laminated body, the magnetic assembly having the above structure is efficiently manufactured at a low price. It

The magnet slots of the magnetic plate are each closed holes, and the magnet slots in the stack formed by these magnet slots may be formed as through holes that are open only at both ends thereof.

Alternatively, each of the magnet slots of the magnetic plate is a hole opened in the peripheral edge of the magnetic plate, and the opening end of the hole has a width narrower than the inside of the hole, and these magnet slots form the inside of the laminated body. The magnet slots formed at both ends thereof are also open to the side wall of the laminated body, and the width of the opening of the magnet slot formed in the laminated body to the side wall of the laminated body is determined by the width of the magnet slot of the magnet slot. It may be smaller than the internal width.

[Embodiments] Hereinafter, embodiments of the present invention will be described in detail with reference to the drawings. Similar parts are provided with similar reference numerals throughout the several views.

FIG. 1 shows an example of a permanent magnet motor. The permanent magnet motor 11 includes a rotor assembly 13 suitably supported for rotation with respect to a stator 15. The rotor 13 includes a rotor shaft 17, to which a stack of magnetic plates 19 having a series of magnet slots is suitably attached,
Usually, a plurality of magnet plates (4 in this example) are provided in the magnet mounting space formed by the magnet slots of each magnetic plate in these magnet plate laminated bodies.
Individual rectangular permanent magnets 21 are attached.

Each of the stacks 19 has a series of holes. For example, all of the magnetic plates have a central hole 23 and a plurality (eg 28) of rotor cage slots 25 located around the periphery of each magnetic plate. Between the car slot 25 and the central hole 23 there is provided a permanent magnet slot, designated 43 in FIG. 3, for receiving a permanent magnet. A pair of slots 37 forming a magnetoresistive barrier are provided between the magnets 43. These barriers may be filled with aluminum during the die casting process.

A substantially V-shaped magnet slot 43 is formed in the laminated plate. In the space for magnets formed in the magnetic plate laminate by these magnet slots 43, Delco Remy (Delco Remy)
The magnet is cast at this location using a low shrinkage ferromagnetic material such as that sold under the registered trademark Magnequench MQ-1 by My). This particular material is 98% boron-neodymium-iron with 2% epoxy binder and is believed to have been manufactured according to US Pat. No. 4,496,395. This particular material is filled into slot 43 in powder form and then compressed with a force of about 66 tons per square inch (426 tons / cm ² ). The material is then cured at 300 ° to form the magnetic material as a solid piece in the slot 43 in the stack of magnetic plates. This not only allows the magnet to be formed in place within the magnet slot of any shape to match the shape of the magnet slot, but also allows the magnet to be held in place with low cost To The material that is hardened in the magnet slot remains unmagnetized during the hardening process. Further, this strong magnetic material has a property that it hardly shrinks during curing. Therefore, the magnet is formed without a gap between the magnet itself and the laminated body of the magnetic plates 41. After the magnet (but not yet magnetic) is formed in place, the magnet is magnetized in place to form, for example, a dipole rotor.
Of course, various oxidation methods may be used depending on the particular magnetic structure that the rotor is desired to have.

In FIG. 4, a magnetic plate according to another embodiment of the present invention is shown with reference numeral 51. The magnetic plate includes four magnetoresistive barrier slots 37, with a pair of rotor cage slots between each pair of magnetoresistive barrier slots 37.
25 are arranged. Further, reference numeral 53 of the magnetic plate 51
The magnet slots marked with are substantially arcuate. Also in this case, the magnet material described in FIG. 3 is filled in-situ into the arc-shaped slots of the laminated body of the magnetic plates 51, and the magnet is formed in the arc-shaped slots by the same process as that described in FIG. Formed in pairs. The magnet thus formed can have any desired polarity. For example, the north pole of the magnet on the right side in FIG. 4 may be located outside the arc of the magnet, and the north pole of the magnet on the left side may be located inside the arc of the magnet. The invention also frees the designer from the restriction that only permanent magnets of a particular shape can be used. If the designer desires a particular magnetic flux and polarity that is not available in one configuration, various arbitrary magnet configurations can be selected regardless of the commercially available permanent magnet configurations. The designer
The best permanent magnet assembly can be made, rather than the best assembly made from commercially available components.

In FIG. 5 showing still another embodiment of the present invention,
A magnetic plate 61 similar to that shown in FIG. 4 is a pair of magnetoresistive barrier slots having a generally anvil shape outside the rotor cage slot 25 located around the pair of arc magnet slots 53 and their peripheries. Contains 63. These magnetoresistive barrier slots may be filled with aluminum or other suitable material during the die casting process. Thereafter, magnetizable material is inserted into the slot 53 and a permanent magnet is formed therein in situ as described above.

Although the present invention has been described above with respect to rotor assemblies, the present invention is not so limited. As shown in FIGS. 6 and 7, the present invention is equally applicable to stator assemblies for dynamoelectric machines, and is generally applicable to any permanent magnet assembly.

The stator assembly 71 shown in FIG. 6 includes a stack of magnetic plates 73 of suitable magnetic material. Each magnetic plate has a plurality of slots 75 formed therein, and within these magnet slots, a plurality of permanent magnet pieces 77 are in place, as previously described for the rotor assembly. It is formed.
In the embodiment shown in FIG. 6, eight permanent magnet pieces 77 with eight magnet slots 75 are shown. These are magnetized to form a stator of at least 8 poles. Of course, this number is exemplary. Any desired number of poles can be formed in this way. The slots 75 of the stator 71 differ from the magnet slots of the previous embodiment in that they open into the internal center hole 79 of the stator assembly. The magnet slots 75 are smaller in width at their openings than inside the magnet slots,
Note, therefore, that the magnet strips formed within these magnet slots are retained in their respective slots. Of course, when forming the ruler piece 77, it is necessary to provide some device to prevent the powdered material from flowing out of the inner opening of the magnet slot 75 while the powdered material is compressed or hardened. is there. It will be apparent that a shape with similarly open peripheral magnetic slots may also be used for the rotor assembly. In each case, the magnetic plate is one continuous piece, or the shape of the magnet slot is shaped so that the magnet pieces formed in the magnet slot are held in that position. is necessary.

An apparatus 81 suitable for compressively filling magnetizable material in the magnet slots of a stack of magnetic plates as shown in FIGS. 3-5 is shown in FIGS. 8 and 9. There is. This device includes a cylindrical collar 83 which bears against a lateral force a rotor 85 made of a magnetic plate as shown in FIG. Since the force applied to compress the magnetizable material is large, the collar 83 and the support member of the device 81 are preferably made of tool steel or similar material. The collar 83 and the rotor 85 are mounted on a tool steel base 87. The pedestal 87 includes a pedestal 89 suitable for supporting the rotor 85 from below. Rotor 85 is bolt
It is properly attached to the base 87 by 91. Bolt 91 is a stand
It extends upwards from the bottom of 87 through the center of rotor 81 and is tightened by screw washers 93 at the top of the assembly.
Of course, this bond need not be particularly strong. This is because this coupling force acts in the same direction as the compressive force applied to the rotor 85. Bush 95 if needed
May be placed around the bolt 91 to fill the center hole of the rotor.

The rotor 85 includes a pair of magnet slots 97 in which the magnetizable particles are filled. Device 81
It includes a plunger 99 having a pair of downwardly extending ears 101 shaped to fit precisely into a slot 97 filled with magnetizable material. When a force is applied in the direction indicated by the arrow in FIG. 9, the magnetizable material in magnet slot 97 is compressed. If the magnetic plates of the rotor 85 are twisted, it is desirable to use appropriately shaped plungers 99 on both the top and bottom of the slots 97 so that all magnetizable particles are fully compressed.

Each of the rotors of the above-described embodiments has a cage structure, but the present invention is not limited thereto. In Figure 10,
A rotor magnetic plate 105 of a suitable ferromagnetic material is shown having a central hole 107 for the rotor axis and a pair of arcuate magnet slots 109, but no cage slots. In this example, the magnetic plates of the rotor stack are suitably secured together by an adhesive or the like before the magnetizable powder is filled into the magnet slots 109 and compressed.

From the above description, it will be appreciated that the various objects and features of the invention are achieved and other advantageous results attained.

Although the present invention has been described above with reference to particular preferred embodiments, it is not intended that the invention be limited to these embodiments, and various other embodiments are possible within the scope of the invention. It will be apparent to those skilled in the art.

BRIEF DESCRIPTION OF THE DRAWINGS FIG. 1 is a front view of a main part of a dynamo electric machine using a rotor assembly to which the present invention is applied. FIG. 2 is a sectional view showing the structure of the rotor assembly shown in FIG. FIG. 3 is a plan view showing an embodiment of a magnetic plate constituting the rotor assembly as shown in FIGS. 1 and 2. FIG. 4 is a plan view of another embodiment of the magnetic plate used in the present invention. FIG. 5 is a plan view showing still another embodiment of the magnetic plate used in the present invention. FIG. 6 is a plan view showing one embodiment of the stator assembly manufactured according to the present invention. FIG. 7 is an elevational view of the stator assembly shown in FIG. FIG. 8 is a plan view showing an apparatus used for compressing the powder of the ferromagnetic plate filled in the magnet slot of the rotor laminated body composed of the magnetic plates shown in FIGS. 3 to 5. FIG. 9 is a sectional view taken along the line 11-11 in FIG. FIG. 10 is a plan view showing still another embodiment of the magnetic plate used in the present invention. 11 ...... Permanent magnet motor, 13 ...... Rotor assembly, 15 ...... Stator, 17 ...... Rotor shaft, 19 ...... Magnetic plate, 23 ...... Central hole,
25 …… Car slot, 27 …… Magnetic slot, 29 …… End ring, 37 …… Magnetic resistance barrier slot, 41 …… Magnetic plate, 43 …… Magnetic slot, 51 …… Magnetic plate, 53 …… Slot, 61 ...... Magnetic plate, 63 ...... Magnetic resistance barrier slot,
71 ... Stator assembly, 73 ... Magnetic plate, 75 ... Magnet slot, 77 ... Magnet piece, 79 ... Central hole, 81 ... Fixture, 83 ...
… Cylindrical collar, 85 …… Rotor, 87 …… Stand, 89 …… Pedestal, 91 …… Bolt, 93 …… Washer, 95 …… Bush, 97 …… Slot, 99 …… Plunger, 105 …… Rotating Child magnetic plate, 107 ... central hole, 109 ... magnet slot

Claims (4)

(57) [Claims] 1. A laminate of magnetic plates in which magnetic plates each having a magnet slot are stacked so that the magnet slots are substantially aligned with each other and corresponding magnet slots are formed; A magnetic assembly having a permanent magnet piece formed by hardening and magnetizing powder of a ferromagnetic material filled in the magnet slot in the slot. 2. A magnetic assembly according to claim 1, wherein the magnet slots of the magnetic plate are closed holes, and the magnet slots formed by the magnet slots are at both ends thereof. A magnetic assembly formed as a through hole that is open only at the. 3. A magnetic assembly according to claim 1, wherein each magnet slot of said magnetic plate is a hole opened at the peripheral edge of said magnetic plate, and the opening end of said hole is located inside said hole. With a narrow width, the magnet slots formed in the laminate by these magnet slots are open at both ends and also on the side walls of the laminate, and the magnet slots formed in the laminate are A magnetic assembly in which the width of the opening to the sidewall of the stack is less than the width of the interior of the magnet slot. 4. A process of stacking magnetic plates each having a magnet slot so that the magnet slots are substantially aligned with each other to form a laminate having corresponding magnet slots formed therein, and a step of forming the laminate. Filling the magnet slot with ferromagnetic powder, and compressing and curing the ferromagnetic powder in the magnet slot of the stack to form a solid ferromagnetic body. Magnetizing the solid body of ferromagnetic material in the magnet slots of the stack.